Fix clang's use of DenseMap iterators after r86636 fixed their constness.
Patch by Victor Zverovich!



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86638 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ExplodedGraph.cpp b/lib/Analysis/ExplodedGraph.cpp
index 0dc81a4..3b339ff 100644
--- a/lib/Analysis/ExplodedGraph.cpp
+++ b/lib/Analysis/ExplodedGraph.cpp
@@ -273,7 +273,7 @@
 
 ExplodedNode*
 InterExplodedGraphMap::getMappedNode(const ExplodedNode* N) const {
-  llvm::DenseMap<const ExplodedNode*, ExplodedNode*>::iterator I =
+  llvm::DenseMap<const ExplodedNode*, ExplodedNode*>::const_iterator I =
     M.find(N);
 
   return I == M.end() ? 0 : I->second;